James park



@uiten gisten lstwt @fitta JAMES PARK, JR., 0F PITTSBURG, PENNSYLVANIA.

Letters PatentNo. 78,477, dated June 2, 1868.

IMPROVEMENT IN.4 THE vll/[ANUIAGI'URE OP PLATES QI' (/'OMBINED` STEEL AND IEON.-

@he rlphnh referat in .in tlpse gettati@attent nnb mating :grit if the traire.

TO ALL WHOM IT MAY CONGERN:

i, Be it known that I, JAMES PARIQJr., of the city -ot"Pittsburg, in the county of Allegheny, and State of Pennsylvania, have invented a new and useful Improvement in Manufacture ot' Metal Plates of Combined Steel and Iron; and I do hereby declare the following to be a fall, clear,` and exact description thereof.

It is very important, for 'various purposes in the arts and manufactures, to produce plates or sheets of metal which shall combine the hardness and susceptibility to polish, and tempering qualities', of high-tempered steel,

with the toughness, strength, and susceptibility to formativeaction ot' dies or swag-es possessed by wrought iron and'otherfsoi't fibrous metals. 'Ilius, in the manufactureof ploughs', it is desirable to have the hard, highlypolished, anddurable surface which can be given to high-tempered steel, and` which thepsofter orloWer-tempered steel, such as German or blister steel,'. will nottalce. But high-tempered steel plates cannot he moulded into shape, and must be'moulded before being tempered, but will warp an'd crack in the temperinger hardening process. l

In the manufacture of tire and burglar-proof safes, it is highly important lthat the metal plates of which they'are composed should-not only be smooth kand even in. surface, but also so hard as to resist the action of boring and cutting-tools, andsov tough andstrong as not to be cracked or broken by blows from asledgehammer.

Such requirements arsimpo'ssible to be fulfilled' with the use of ordinary castor wrought steel, so that the Jplates nre sure to be either` so brittle a"s to be readily fractured, o r so soft as to be easily cut or drilled, 1and in either case the tempering process'employed to harden the steel is liable to Warp the plates, and render them useless for the requiredl pui-poemas they eannotbe brught'rback to shapeafter having been hardened.

In order to prevent theisteel plates from cracking orbrcaking -in the'h'ardening process, it is necessary touse steel oi'V a comparatively low, mild, or soft temper, but such steel-.cannot be hardened sufficiently to resist the tools of theburglarl It, on the other hand, high-tempered or hard steel is used, such as is susceptible of a high degree ot' hardness, the plates arc so brittle as to be unable to resist the force ot' blows which will readily shatter the safe to pieces.

In hardening the steel'plates, they are very apt to warp or crack, and become so misshapen as to be unfit for use, or, if they had been previously'moulded intoany rendi-red shape by dies o'r otherivise, the tempering process will cause them to change their form, which cannot be restored or the plates straightened Without being softened, and thus rendered useless for the purpose intended.

In casting molten steel against a heated slab of Wrought iron, there is no difficulty in forming'a plate or ingot which shali ne susceptible of being rolled orhammered out in'to plates'possessng externally all the hard- 'nessof thehcst cast steel, combined with greater toughness and strength than is possessed by the softest kinds of steel, such as German orblister steel. But a diculty still occurs, in the fact that when the molten steel is cast around the heated slab' of wrought iron', the carbon of the steel penetrates -the iron, carbonizing'it to such a degree as to impair 'its toughness and strength, and renderit more brittle than goed Wrought iron. i I In order to secure plates for the construction of safes, plough-plateaand other purposes, possessing the requisite degree of toughness with the greatest exterior hardness, I have invented a mode of manufacturing platesot` combined steel and iron, which accomplishes the desired result` l To enable others skilled in the art to use my inventiomI proceed to describe the process which I employ.

In the accompanying drawings- Figure 1 is a perspective representation of the 'mould which I use for forming thesteel and iron slabs.

Figure 2 is a section of the mould through m x, iig. 1.

, The mould which I use for casting` the s teel on to the iron to form the slab is made of cast iron, divided vertically intotwo parts, A. and B, which tit. together with a related joint, and are held in place by bands a a, tightened by wedges b b, or otherwise, as may be'most convenient. v I

The part or division of the mould is made in the plane of the t'acc yof the iron slab to which the steel'is t0 be united. v "s The cavity of the piece A of the mould is a little wider across than -that of the piece B, thus Aforming ar shoulder on eachsideatc e, for the slab of wroughtiron, D, to rest against when placed within the cavity ofthe piece A of the mould 'c vhich it fills, the outer surface of the Wrought-iron slab'tonching theinner surface of the piece A. The cavity of the piece B of the mould is to receive the melted steel.

The operation is as follows: i

A slub,I), of good Wrought iron, of the required size and shape' to'it the piece A ofthe muld,'is heated red hot,'eithcr on both sides or only on that side against which the steel is to be cast, and placed Within the piece A, when theV mould is shut, and melted cast steel of high or hard temper is turned-into the cavity of the piece B of the mould against the surfacezof the red-hot piece of. irom -When the cast steel in the mould is sulciently set, the bands a cz are removed, the mould is opened, and the ingot is taken out. Y

As the'steel is cast against one side-only of the wrought-iron slab, the` iron is oarbonized, if at all, only on the side next the steel, the outer surface of the iron preserving its 'soft and fibrous nature. I

The ingots, thus formed, are then removed to a furnace prepared to receive them, having openings of the size oi' the ingot, intowhich the wrought-ironside of the inglot is inserted, so as toexpose it tothe heat ofthe furnace, while the steel side isleft outside of thefurnace, and not exposed to the action of the lfire. Iy this' means these ingots'are heated on' their iron side to a red welding heat, while the steel sidc,'which would be injured by the-burning of the carbon at-sucha heat, isproteeted and kept comparatively cool.

Two ingots, each heated, as above described, on one side only, are placed together, with their heated iron sides in Contact, 'the steel sides forming thel outer surfaces, and the double ingot thusformed is placed-within an ordinary l1eatig-f`urnace until the whole mass is sufficiently heated to be rolled or hammered. As the wrought iron forming the inside of tliis'double ingot was somueh hotter than the steel, .when placed in the heating-furnace, the iron is raised to a high welding heat before the steel has passed a safe heat, andthe steel vwill have received no injury, when the whole massfisfsuiciently heated to be hammered or rolled. The ingot isthen -removed from the fur-nace, and immediately subjected to the hammer, or passed between rolls, until the two. pieces are perfectly welded together, and is, either wit-h or without reheating, further rolled until it is reduced to the proper thickness required bythe manufacturer.

In order to secure greater strength. and toughness to the sheets, I sometimes heat a slab of wrought ir'on, n of thc'requisite sine and shape, to a high welding heat, and place it between two oftheingots,the i1'on surfaces of the two ingots, prcviouslyvheated as before described, being placed in contact with the iron slab, which thus gives a central stratum of wrought iron, which has not been exposed'to the danger of carbonization4 by the casting of steel against it. The ingot thusmade is hammered or rolled, and reduced as before described.

In place of -wrought iron, other malleable'and fibrousfmetal may be used in the same ivay, but for ordinary purposes good wrought iron will be preferred. l v

By this process I have described, I secure sheetsor plates of metal having a central stratum of tough malleable metal, and an outer skin' or coatingr of steel of any desired hardness or vtemper, suoli as cannot be produced either by any ordinary process of Welding, or by casting the steel on both sides of a wrought-iron sla-b, and then rolling it down to the proper thickness.

Plates, such as I have described, caube made so strongand tough, and-at the same time' sohard, as4 to be proef against either boring, cutting, or breaking, as the perfect union of the high-tempered steel with the wrought iron, or other soft and brous metal, prevents the separation of' the steel and'iron, and enables it to resist the blows yof a sledgehammer, while it is susceptible, before it is hardened, of being' moulded byfswages or dies, or hammered, and will retain the desired shape during the process of tempering without warping or cracking, the fibrous texture of the wrought iron or soft metal being preserved, as yvell as the hardness, impcnctrability, and susceptibility to'polish of thc highly-tempered steel.

What I claim as new in-Amy method of making ingots, plates, or sheets of combined cast steel and.wrought iron, or other tough fibrous metal from ingots produced by casting high-tempered steel on 'one side cnly of a slab of wrought iron or other fibrous metal, isp Giving a welding-heat to the iron or fibrous metal side only of the ingots, in the manner hereinbefore described, and then uniting these surfaces by welding them together, either with or without an interposed layer of wrought iron or otheribrous and malleable metal, substantially as hereinbefore set forth.

In testimony whereof, I. the said JAMES PARK, Jr., have hereunto set my hand,

' JAMES PARK, JR.

Witnesses:

A. S. NICHOLSON, Guo. H: CHRISTY; 

